Cumputer intrusion

From: Mircea Pleteriu (mpleteriu_at_newsgroup.nospam)
Date: 06/08/05 

Date: Wed, 8 Jun 2005 17:15:51 +0300

Hi,

I want to detect when another user enters my computer via the local network.
Is it possible to programatically detect computer intrusion?

Thanks,
    Mircea